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Submission #56167

# Submission time Handle Problem Language Result Execution time Memory
56167 2018-07-10T07:06:25 Z 윤교준(#1582) Mobile (BOI12_mobile) C++11
100 / 100
 376 ms 57180 KB 
#include <bits/stdc++.h>
#define pb push_back
#define eb emplace_back
#define sz(V) ((int)(V).size())
#define allv(V) ((V).begin()),((V).end())
#define befv(V) ((V)[(sz(V)-2)])
#define sorv(V) sort(allv(V))
#define revv(V) reverse(allv(V))
#define univ(V) (V).erase(unique(allv(V)),(V).end())
#define clv(V) (V).clear()
#define upmin(a,b) (a)=min((a),(b))
#define upmax(a,b) (a)=max((a),(b))
#define INF (0x3f3f3f3f)
#define INFLL (0x3f3f3f3f3f3f3f3fll)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<int, ld> pid;
ld pw(ld n) { return n*n; }

const int MAXN = 1000005;

vector<pid> G;

ll A[MAXN], B[MAXN];
int X[MAXN], Y[MAXN];

ld Ans;
int N, L;

ld naive(ld x) {
	ld ret = INFLL;
	for(int i = 1; i <= N; i++)
		upmin(ret, pw(x-X[i]) + pw(ld(Y[i])));
	return ret;
}
ld f(int i, ld x) { return x*x + x*A[i] + B[i]; }
void upd(int i, ld x) {
	if(x < 0 || ld(L) < x) return;
	upmax(Ans, f(i, x));
}

int main() {
	ios::sync_with_stdio(false);

	cin >> N >> L;
	{
		vector<pii> V;
		for(int i = 0, x, y; i < N; i++) {
			cin >> x >> y;
			V.eb(x, abs(y));
		}
		sorv(V); univ(V);
		
		N = sz(V);
		for(int i = 1; i <= N; i++)
			tie(X[i], Y[i]) = V[i-1];
	}

	for(int i = 1; i <= N; i++) {
		A[i] = ll(X[i]) * (-2);
		B[i] = ll(X[i]) * X[i] + ll(Y[i]) * Y[i];
	}

	for(int i = 1; i <= N; i++) {
		for(; 1 < i && i <= N && A[i-1] == A[i]; i++);
		if(N < i) break;

		for(; !G.empty();) {
			int j; ld X; tie(j, X) = G.back();
			ld x = ld(B[i]-B[j]) / ld(A[i]-A[j]) * (-1);
			if(X < x) {
				G.eb(i, x);
				break;
			}
			G.pop_back();
		}
		if(G.empty()) G.eb(i, ld(0));
	}

	for(int i = 0; i < sz(G); i++)
		upd(G[i].first, G[i].second);
	
	upmax(Ans, max(naive(0), naive(L)));

	printf("%Lf\n", sqrt(Ans));
	return 0;
}

Subtask #1
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 376 KB Output is correct
2 Correct 2 ms 548 KB Output is correct
3 Correct 1 ms 548 KB Output is correct
4 Correct 3 ms 548 KB Output is correct

Subtask #2
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 548 KB Output is correct
2 Correct 3 ms 548 KB Output is correct
3 Correct 2 ms 548 KB Output is correct
4 Correct 1 ms 548 KB Output is correct

Subtask #3
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 644 KB Output is correct
2 Correct 4 ms 860 KB Output is correct
3 Correct 4 ms 860 KB Output is correct
4 Correct 4 ms 860 KB Output is correct

Subtask #4
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 860 KB Output is correct
2 Correct 5 ms 872 KB Output is correct
3 Correct 5 ms 872 KB Output is correct
4 Correct 6 ms 872 KB Output is correct

Subtask #5
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 872 KB Output is correct
2 Correct 5 ms 872 KB Output is correct
3 Correct 5 ms 872 KB Output is correct
4 Correct 6 ms 876 KB Output is correct

Subtask #6
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 876 KB Output is correct
2 Correct 4 ms 876 KB Output is correct
3 Correct 5 ms 876 KB Output is correct
4 Correct 6 ms 876 KB Output is correct
5 Correct 5 ms 876 KB Output is correct

Subtask #7
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 2824 KB Output is correct
2 Correct 34 ms 2824 KB Output is correct
3 Correct 30 ms 2824 KB Output is correct
4 Correct 52 ms 2824 KB Output is correct
5 Correct 20 ms 2824 KB Output is correct

Subtask #8
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 2824 KB Output is correct
2 Correct 23 ms 2824 KB Output is correct
3 Correct 27 ms 2824 KB Output is correct
4 Correct 45 ms 2824 KB Output is correct
5 Correct 42 ms 2824 KB Output is correct

Subtask #9
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 28 ms 6944 KB Output is correct
2 Correct 49 ms 6944 KB Output is correct
3 Correct 43 ms 6944 KB Output is correct
4 Correct 39 ms 6944 KB Output is correct
5 Correct 27 ms 6944 KB Output is correct

Subtask #10
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 33 ms 6944 KB Output is correct
2 Correct 32 ms 6944 KB Output is correct
3 Correct 28 ms 6944 KB Output is correct
4 Correct 40 ms 6944 KB Output is correct
5 Correct 34 ms 6944 KB Output is correct

Subtask #11
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 6944 KB Output is correct
2 Correct 32 ms 6944 KB Output is correct
3 Correct 28 ms 6944 KB Output is correct
4 Correct 40 ms 6944 KB Output is correct
5 Correct 33 ms 6944 KB Output is correct

Subtask #12
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 156 ms 28872 KB Output is correct
2 Correct 158 ms 28872 KB Output is correct
3 Correct 150 ms 28872 KB Output is correct
4 Correct 216 ms 28872 KB Output is correct
5 Correct 167 ms 28872 KB Output is correct

Subtask #13
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 160 ms 28872 KB Output is correct
2 Correct 155 ms 28872 KB Output is correct
3 Correct 138 ms 28872 KB Output is correct
4 Correct 184 ms 28872 KB Output is correct
5 Correct 168 ms 28872 KB Output is correct

Subtask #14
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 198 ms 47628 KB Output is correct
2 Correct 213 ms 47628 KB Output is correct
3 Correct 253 ms 47628 KB Output is correct
4 Correct 234 ms 47628 KB Output is correct
5 Correct 207 ms 47628 KB Output is correct

Subtask #15
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 211 ms 47628 KB Output is correct
2 Correct 211 ms 47628 KB Output is correct
3 Correct 251 ms 47628 KB Output is correct
4 Correct 228 ms 47628 KB Output is correct
5 Correct 229 ms 47628 KB Output is correct

Subtask #16
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 337 ms 50048 KB Output is correct
2 Correct 242 ms 50048 KB Output is correct
3 Correct 287 ms 50048 KB Output is correct
4 Correct 267 ms 50048 KB Output is correct
5 Correct 278 ms 50048 KB Output is correct

Subtask #17
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 227 ms 50048 KB Output is correct
2 Correct 220 ms 50048 KB Output is correct
3 Correct 198 ms 50048 KB Output is correct
4 Correct 266 ms 50048 KB Output is correct
5 Correct 234 ms 50048 KB Output is correct

Subtask #18
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 296 ms 52460 KB Output is correct
2 Correct 254 ms 52460 KB Output is correct
3 Correct 248 ms 52460 KB Output is correct
4 Correct 339 ms 52460 KB Output is correct
5 Correct 276 ms 52460 KB Output is correct

Subtask #19
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 254 ms 52460 KB Output is correct
2 Correct 243 ms 52460 KB Output is correct
3 Correct 225 ms 52460 KB Output is correct
4 Correct 315 ms 52460 KB Output is correct
5 Correct 288 ms 52460 KB Output is correct

Subtask #20
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 350 ms 57180 KB Output is correct
2 Correct 309 ms 57180 KB Output is correct
3 Correct 299 ms 57180 KB Output is correct
4 Correct 376 ms 57180 KB Output is correct
5 Correct 338 ms 57180 KB Output is correct

Subtask #21
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 318 ms 57180 KB Output is correct
2 Correct 305 ms 57180 KB Output is correct
3 Correct 285 ms 57180 KB Output is correct
4 Correct 375 ms 57180 KB Output is correct
5 Correct 339 ms 57180 KB Output is correct